Question

A boiler burns a biofuel, which is a mixture of 91 % Cellulose (C6H1005) and 106 I6 Paracoumaryl alcohol (C9H1002) in mass. (a) Write down the stoichiometric combustion equation of this biofuel. [8 marks] (b) The biofuel and excessive air are supplied to the combustion chamber at 298 K. The measured adiabatic flame temperature of the combustion of the biofuel with excess air is 2225 K. Determine the percentage excess air of this combustion using the constant averaged specific heats: (CO2: 55 kJ/kmol-K, H2O: 43 kJ/kmol-K, N2: 33 kJ/kmolK, Oz: 35 kJ/kmol-K). Enthalpy of formation C6H1005 = -261,650 kJ/kmol, C9H10O2 = -284,600 kJ/kmol CO2 = -393,500 kJ/kmol, H2O = -241,800 kJ/kmol [5 marks] (c) Calculate the air/fuel ratio by volume for another combustion of this biofuel with 100% excess air.